Honing is known, for example, as one of machining methods for finishing the inner circumference of works precisely. In honing process, a honing tool and a work are set in a relatively floating state, and rotary and reciprocal motions are given to the honing tool, and the inner circumference of the work is finished precisely while expanding the wheel of the honing tool by a wedge or cone.
Recently, as an apparatus for efficiently honing the inner circumference of works as mass production pieces such as the inner circumference of automotive parts, an automatic honing system has been developed for honing the works conveyed at specific intervals sequentially and continuously by means of plural honing machines arrayed in a line.
An example of such automatic honing system is shown in FIG. 30, in which a work conveying route a is formed in a loop, and a work loading b, a work machining section c, and a work unloading d are arrayed in this work conveying route a.
At the work loading b, works W supplied in line by a work feeder e such as parts feeder are mounted on a honing jig g waiting at a detaching position P of the work conveying route a by means of a robot device f. The honing jig g holding the work W is sent to a position of a prepared hole detecting device i by means of a delivery device h, and the inside diameter of the prepared hole of the work W is detected by the prepared hole detecting device i.
In succession, while holding the work W, the honing jig g is sent to the work machining section c, in which the work W is conveying in a cycle sequentially comprising a rough honing machine k, a first detecting device 1, an intermediate honing machine m, a second detecting device n, a finish honing machine o, and a third detecting device p, by means of a transfer device j, and is positioned at each machine position, so that the specified honing process is executed sequentially and automatically.
The work W completely finished in the work machining section c is cleaned by a brush device q, and is sent out to the detaching position P by means of a discharge device r, a return device s, and a pushing device t in the work unloading d, and is sorted according to the result of measurement by the third detecting device p by the robot device f at the work loading b again, and a conforming work is put into a conforming piece chute u, and a defective piece is put into a reject chute v.
This automatic honing system is designed as a tailored machine for specific works W depending on the shape, dimensions and machining conditions of the works, and all sections a, b, c, d are integrally fixed on a large machine frame (not shown), and are driven by a control device x which controls the entire system in batch.
In such system configuration designed as a tailored machine for specific works W, the following problems were known.
(1) The number of process of honing is determined by the accuracy of the shape of prepared holes of the works W, stock removal, and required shape accuracy, but the accuracy of shape of prepared holes and stock removal are not stable in the stage of trial production.
Accordingly, in the configuration in which all sections a, b, c, d are integrally fixed on a large machine frame, and the entire system is controlled by one control device x in batch, the number of process cannot be determined until reaching the final stage.
(2) By the same reason, if the prepared hole accuracy of the works W is changed or if the required machining accuracy of the works W is changed, the number of process cannot be changed.
(3) Also by the same reason, it is hard to determine the capital investment if prediction of the production quantity of works W is difficult.
(4) Since this is a tailored machine designed for specific works W, when production of the specific works W is stopped, the mechanical configuration of the entire system must be modified in order to use for machining of other works differing in shape, dimension and machining conditions, or if such modification is impossible, the entire system must be discarded, and the apparatus cost is very high.
(5) Since the sections a, b, c, d are composed as one integral apparatus, hydraulic units as drive sources for individual devices, coolant tanks used in machining, and others shared among individual constituent devices are large in size and installed separately, and the entire system is large and complicated, and the apparatus cost is soaring.
Most of these problems are not limited to this automatic honing system, but were common among automatic machining systems for machining machine parts and other mass production pieces sequentially and continuously by using plural machine tools arrayed in a line.
The invention is devised in the light of the problems of such prior art, and it is hence an object thereof to present a processing cell of an automatic machining system having a small, lightweight and simple structure, capable of determining or changing the number of process easily, easy in design, and lowered in the apparatus cost.
It is other object of the invention to present a structure of an automatic honing system comprising a plurality of such processing cells.